I would like to know what type of bottle this is and its possible value. The bottom of the bottle has a 20 followed by the circle/diamond symbol followed by a 51. Below that is a 3A, then Duraglas. The bottom line is worn but looks like 2578-C. The label appears to be painted on as there is not a plastic sticker. The majority of the outside of the bottle is bumpy. To the bottom left of the label, on the side of the bottle, there is a round indent. There are no chips or cracks, but a few slight scratches around the opening. The bottle came from Boyes Hot Springs in California. From my research, I think it was made in 1951 at the Duraglas plant in Oakland, CA (which started in 1937), and is a machine-made bottle. Any information on how to research this bottle or where to sell it would be appreciated.